Before exiting or entering a manual wheelchair, a user typically has to lean down and either swing away the footrest hangers to the side or lift the footrests to the vertical retracted position. Either motion can be difficult for some manual wheelchair users, particularly those with limited upper extremity mobility. Consequently, these users will constantly require help from caregivers to retract the footrest before they get in and out of wheelchairs. Retracting the footrests is also an awkward task for caregivers, who will have to bend over or crouch to raise the footrests.
After retracting the footrests the user must rise from a seated to a standing position to exit the wheelchair. Sit-to-stand is known to be a biomechanically challenging task in the older adult population. Research in sit-to-stand among older adults reveals that knee extensor strength can be a limiting factor in successfully rising from a chair. Research has also shown that functionally impaired seniors attempt to increase postural stability during sit-to-stand by flexing the trunk forward prior to rising, thus decreasing the center of mass/base of support (COM/BOS) separation at the instant of liftoff. Accordingly a method to guide an older user into a more functionally appropriate forward position before standing would be beneficial.
Previous attempts have been developed to address footrest retraction, including: U.S. Pat. Nos. 6,422,653; 7,347,497; 6,880,845. However, none of these devices possess mechanisms that additionally assist or support users with the sit-to-stand motion after the footrests have been retracted.